1. Field of the Invention
The present invention relates to data storage networks, and especially networks implementing SAN (Storage Area Network) functionality or the like. More particularly, the invention concerns the discovery of network information for network management use in a data storage network environment.
2. Description of the Prior Art
By way of background, data storage networks, such as SAN systems, provide an environment in which data storage devices are managed within a high speed network that is dedicated to data storage. Access to such networks is provided via one or more storage manager servers that handle data storage requests (e.g., copy, backup, etc.) from data client nodes (data clients) via conventional LAN (Local Area Network) or WAN (Wide Area Network) connections. The storage manager servers are programmed data processing platforms that maintain interfaces to the client-side LAN/WAN and to the storage-side devices that define the data storage network's pool of peripheral storage. These storage devices may include any number of interconnected magnetic disk drive arrays, optical disk drive arrays, magnetic tape libraries, etc. In all but the smallest data storage networks, the required inter-connectivity is provided by way of arbitrated loop arrangements or switching fabrics, with the latter being more common. Typical inter-connectivity components include copper or fiber optic cables, hubs, bridges, gateways, switches, directors, and other data communication equipment designed for high speed data transfer between and among all of the interconnected storage manager servers and storage devices that comprise the data storage network.
One advantage provided by a data storage network is that data belonging to an organizational enterprise can be centrally managed via high level management systems regardless of where the data is located or how it is physically stored and accessed. The management function may be provided at several levels by way of commonly available software tools, including storage management, storage resource management, and storage area network management applications. These applications are variously responsible for monitoring the network storage devices, and their logical integration with the storage manager servers, the network interconnectivity components, and the storage manager servers themselves.
A function required by the aforementioned management software is the ability to discover the various devices and components that comprise the data storage network configuration, identify their attributes, and map their physical and logical relationships. Conventional data storage network management applications use “agents” within the data storage network to perform the required discovery. An agent is a logical entity that resides on a network node, such as a storage manager server, a storage device or a network interconnectivity component. The agent is programmed to provide information about some portion of the data storage network to the supervising management application. For any given management application there are often several agents that need to report information because no one agent may have complete information about the data storage network.
The term “discovery poll” refers to the discovery of data storage network information via a management application's agents, and the subsequent processing of that information by the management application. A discovery poll can be triggered for any number of reasons, such as periodic scheduling, on-demand requests, and asynchronous events. Overall, the discovery process is computationally intensive. Discovery polls can occur with high frequency, there may be a number of agents required to obtain complete information, and the information obtained from each agent may be large and complex depending on the size and complexity of the data storage network configuration. Moreover, because new requests for discovery polls can arise while a previous discovery poll is being processed, the discovery processing can become severely backlogged so that undesirable delays occur in fulfilling the processing requests.
It is to solving the foregoing problems that the present invention is directed. In particular, what is required is a way to simplify network management information discovery and reduce the amount of processor intensive computation required to effectively manage a network.